/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <assert.h>
#include <stdlib.h>

#include "uv.h"
#include "internal.h"
#include "handle-inl.h"
#include "stream-inl.h"
#include "req-inl.h"

/*
 * Threshold of active tcp streams for which to preallocate tcp read buffers.
 * (Due to node slab allocator performing poorly under this pattern,
 *  the optimization is temporarily disabled (threshold=0).  This will be
 *  revisited once node allocator is improved.)
 */
const unsigned int uv_active_tcp_streams_threshold = 0;

/*
 * Number of simultaneous pending AcceptEx calls.
 */
const unsigned int uv_simultaneous_server_accepts = 32;

/* A zero-size buffer for use by uv_tcp_read */
static char uv_zero_[] = "";

static int uv__tcp_nodelay(uv_tcp_t* handle, SOCKET socket, int enable)
{
    if (setsockopt(socket,
            IPPROTO_TCP,
            TCP_NODELAY,
            (const char*)&enable,
            sizeof enable)
        == -1) {
        return WSAGetLastError();
    }
    return 0;
}

static int uv__tcp_keepalive(uv_tcp_t* handle, SOCKET socket, int enable, unsigned int delay)
{
    if (setsockopt(socket,
            SOL_SOCKET,
            SO_KEEPALIVE,
            (const char*)&enable,
            sizeof enable)
        == -1) {
        return WSAGetLastError();
    }

    if (enable && setsockopt(socket, IPPROTO_TCP, TCP_KEEPALIVE, (const char*)&delay, sizeof delay) == -1) {
        return WSAGetLastError();
    }

    return 0;
}

static int uv_tcp_set_socket(uv_loop_t* loop,
    uv_tcp_t* handle,
    SOCKET socket,
    int family,
    int imported)
{
    DWORD yes = 1;
    int non_ifs_lsp;
    int err;

    if (handle->socket != INVALID_SOCKET)
        return UV_EBUSY;

    /* Set the socket to nonblocking mode */
    if (ioctlsocket(socket, FIONBIO, &yes) == SOCKET_ERROR) {
        return WSAGetLastError();
    }

    /* Make the socket non-inheritable */
    if (!SetHandleInformation((HANDLE)socket, HANDLE_FLAG_INHERIT, 0))
        return GetLastError();

    /* Associate it with the I/O completion port. */
    /* Use uv_handle_t pointer as completion key. */
    if (CreateIoCompletionPort((HANDLE)socket,
            loop->iocp,
            (ULONG_PTR)socket,
            0)
        == NULL) {
        if (imported) {
            handle->flags |= UV_HANDLE_EMULATE_IOCP;
        } else {
            return GetLastError();
        }
    }

    if (family == AF_INET6) {
        non_ifs_lsp = uv_tcp_non_ifs_lsp_ipv6;
    } else {
        non_ifs_lsp = uv_tcp_non_ifs_lsp_ipv4;
    }

    if (pSetFileCompletionNotificationModes && !(handle->flags & UV_HANDLE_EMULATE_IOCP) && !non_ifs_lsp) {
        if (pSetFileCompletionNotificationModes((HANDLE)socket,
                FILE_SKIP_SET_EVENT_ON_HANDLE | FILE_SKIP_COMPLETION_PORT_ON_SUCCESS)) {
            handle->flags |= UV_HANDLE_SYNC_BYPASS_IOCP;
        } else if (GetLastError() != ERROR_INVALID_FUNCTION) {
            return GetLastError();
        }
    }

    if (handle->flags & UV_HANDLE_TCP_NODELAY) {
        err = uv__tcp_nodelay(handle, socket, 1);
        if (err)
            return err;
    }

    /* TODO: Use stored delay. */
    if (handle->flags & UV_HANDLE_TCP_KEEPALIVE) {
        err = uv__tcp_keepalive(handle, socket, 1, 60);
        if (err)
            return err;
    }

    handle->socket = socket;

    if (family == AF_INET6) {
        handle->flags |= UV_HANDLE_IPV6;
    } else {
        assert(!(handle->flags & UV_HANDLE_IPV6));
    }

    return 0;
}

int uv_tcp_init_ex(uv_loop_t* loop, uv_tcp_t* handle, unsigned int flags)
{
    int domain;

    /* Use the lower 8 bits for the domain */
    domain = flags & 0xFF;
    if (domain != AF_INET && domain != AF_INET6 && domain != AF_UNSPEC)
        return UV_EINVAL;

    if (flags & ~0xFF)
        return UV_EINVAL;

    uv_stream_init(loop, (uv_stream_t*)handle, UV_TCP);
    handle->tcp.serv.accept_reqs = NULL;
    handle->tcp.serv.pending_accepts = NULL;
    handle->socket = INVALID_SOCKET;
    handle->reqs_pending = 0;
    handle->tcp.serv.func_acceptex = NULL;
    handle->tcp.conn.func_connectex = NULL;
    handle->tcp.serv.processed_accepts = 0;
    handle->delayed_error = 0;

    /* If anything fails beyond this point we need to remove the handle from
   * the handle queue, since it was added by uv__handle_init in uv_stream_init.
   */

    if (domain != AF_UNSPEC) {
        SOCKET sock;
        DWORD err;

        sock = socket(domain, SOCK_STREAM, 0);
        if (sock == INVALID_SOCKET) {
            err = WSAGetLastError();
            QUEUE_REMOVE(&handle->handle_queue);
            return uv_translate_sys_error(err);
        }

        err = uv_tcp_set_socket(handle->loop, handle, sock, domain, 0);
        if (err) {
            closesocket(sock);
            QUEUE_REMOVE(&handle->handle_queue);
            return uv_translate_sys_error(err);
        }
    }

    return 0;
}

int uv_tcp_init(uv_loop_t* loop, uv_tcp_t* handle)
{
    return uv_tcp_init_ex(loop, handle, AF_UNSPEC);
}

void uv_tcp_endgame(uv_loop_t* loop, uv_tcp_t* handle)
{
    int err;
    unsigned int i;
    uv_tcp_accept_t* req;

    if (handle->flags & UV_HANDLE_CONNECTION && handle->stream.conn.shutdown_req != NULL && handle->stream.conn.write_reqs_pending == 0) {

        UNREGISTER_HANDLE_REQ(loop, handle, handle->stream.conn.shutdown_req);

        err = 0;
        if (handle->flags & UV__HANDLE_CLOSING) {
            err = ERROR_OPERATION_ABORTED;
        } else if (shutdown(handle->socket, SD_SEND) == SOCKET_ERROR) {
            err = WSAGetLastError();
        }

        if (handle->stream.conn.shutdown_req->cb) {
            handle->stream.conn.shutdown_req->cb(handle->stream.conn.shutdown_req,
                uv_translate_sys_error(err));
        }

        handle->stream.conn.shutdown_req = NULL;
        DECREASE_PENDING_REQ_COUNT(handle);
        return;
    }

    if (handle->flags & UV__HANDLE_CLOSING && handle->reqs_pending == 0) {
        assert(!(handle->flags & UV_HANDLE_CLOSED));

        if (!(handle->flags & UV_HANDLE_TCP_SOCKET_CLOSED)) {
            closesocket(handle->socket);
            handle->socket = INVALID_SOCKET;
            handle->flags |= UV_HANDLE_TCP_SOCKET_CLOSED;
        }

        if (!(handle->flags & UV_HANDLE_CONNECTION) && handle->tcp.serv.accept_reqs) {
            if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
                for (i = 0; i < uv_simultaneous_server_accepts; i++) {
                    req = &handle->tcp.serv.accept_reqs[i];
                    if (req->wait_handle != INVALID_HANDLE_VALUE) {
                        UnregisterWait(req->wait_handle);
                        req->wait_handle = INVALID_HANDLE_VALUE;
                    }
                    if (req->event_handle) {
                        CloseHandle(req->event_handle);
                        req->event_handle = NULL;
                    }
                }
            }

            uv__free(handle->tcp.serv.accept_reqs);
            handle->tcp.serv.accept_reqs = NULL;
        }

        if (handle->flags & UV_HANDLE_CONNECTION && handle->flags & UV_HANDLE_EMULATE_IOCP) {
            if (handle->read_req.wait_handle != INVALID_HANDLE_VALUE) {
                UnregisterWait(handle->read_req.wait_handle);
                handle->read_req.wait_handle = INVALID_HANDLE_VALUE;
            }
            if (handle->read_req.event_handle) {
                CloseHandle(handle->read_req.event_handle);
                handle->read_req.event_handle = NULL;
            }
        }

        uv__handle_close(handle);
        loop->active_tcp_streams--;
    }
}

/* Unlike on Unix, here we don't set SO_REUSEADDR, because it doesn't just
 * allow binding to addresses that are in use by sockets in TIME_WAIT, it
 * effectively allows 'stealing' a port which is in use by another application.
 *
 * SO_EXCLUSIVEADDRUSE is also not good here because it does check all sockets,
 * regardless of state, so we'd get an error even if the port is in use by a
 * socket in TIME_WAIT state.
 *
 * See issue #1360.
 *
 */
static int uv_tcp_try_bind(uv_tcp_t* handle,
    const struct sockaddr* addr,
    unsigned int addrlen,
    unsigned int flags)
{
    DWORD err;
    int r;

    if (handle->socket == INVALID_SOCKET) {
        SOCKET sock;

        /* Cannot set IPv6-only mode on non-IPv6 socket. */
        if ((flags & UV_TCP_IPV6ONLY) && addr->sa_family != AF_INET6)
            return ERROR_INVALID_PARAMETER;

        sock = socket(addr->sa_family, SOCK_STREAM, 0);
        if (sock == INVALID_SOCKET) {
            return WSAGetLastError();
        }

        err = uv_tcp_set_socket(handle->loop, handle, sock, addr->sa_family, 0);
        if (err) {
            closesocket(sock);
            return err;
        }
    }

#ifdef IPV6_V6ONLY
    if (addr->sa_family == AF_INET6) {
        int on;

        on = (flags & UV_TCP_IPV6ONLY) != 0;

        /* TODO: how to handle errors? This may fail if there is no ipv4 stack */
        /* available, or when run on XP/2003 which have no support for dualstack */
        /* sockets. For now we're silently ignoring the error. */
        setsockopt(handle->socket,
            IPPROTO_IPV6,
            IPV6_V6ONLY,
            (const char*)&on,
            sizeof on);
    }
#endif

    r = bind(handle->socket, addr, addrlen);

    if (r == SOCKET_ERROR) {
        err = WSAGetLastError();
        if (err == WSAEADDRINUSE) {
            /* Some errors are not to be reported until connect() or listen() */
            handle->delayed_error = err;
        } else {
            return err;
        }
    }

    handle->flags |= UV_HANDLE_BOUND;

    return 0;
}

static void CALLBACK post_completion(void* context, BOOLEAN timed_out)
{
    uv_req_t* req;
    uv_tcp_t* handle;

    req = (uv_req_t*)context;
    assert(req != NULL);
    handle = (uv_tcp_t*)req->data;
    assert(handle != NULL);
    assert(!timed_out);

    if (!PostQueuedCompletionStatus(handle->loop->iocp,
            req->u.io.overlapped.InternalHigh,
            0,
            &req->u.io.overlapped)) {
        uv_fatal_error(GetLastError(), "PostQueuedCompletionStatus");
    }
}

static void CALLBACK post_write_completion(void* context, BOOLEAN timed_out)
{
    uv_write_t* req;
    uv_tcp_t* handle;

    req = (uv_write_t*)context;
    assert(req != NULL);
    handle = (uv_tcp_t*)req->handle;
    assert(handle != NULL);
    assert(!timed_out);

    if (!PostQueuedCompletionStatus(handle->loop->iocp,
            req->u.io.overlapped.InternalHigh,
            0,
            &req->u.io.overlapped)) {
        uv_fatal_error(GetLastError(), "PostQueuedCompletionStatus");
    }
}

static void uv_tcp_queue_accept(uv_tcp_t* handle, uv_tcp_accept_t* req)
{
    uv_loop_t* loop = handle->loop;
    BOOL success;
    DWORD bytes;
    SOCKET accept_socket;
    short family;

    assert(handle->flags & UV_HANDLE_LISTENING);
    assert(req->accept_socket == INVALID_SOCKET);

    /* choose family and extension function */
    if (handle->flags & UV_HANDLE_IPV6) {
        family = AF_INET6;
    } else {
        family = AF_INET;
    }

    /* Open a socket for the accepted connection. */
    accept_socket = socket(family, SOCK_STREAM, 0);
    if (accept_socket == INVALID_SOCKET) {
        SET_REQ_ERROR(req, WSAGetLastError());
        uv_insert_pending_req(loop, (uv_req_t*)req);
        handle->reqs_pending++;
        return;
    }

    /* Make the socket non-inheritable */
    if (!SetHandleInformation((HANDLE)accept_socket, HANDLE_FLAG_INHERIT, 0)) {
        SET_REQ_ERROR(req, GetLastError());
        uv_insert_pending_req(loop, (uv_req_t*)req);
        handle->reqs_pending++;
        closesocket(accept_socket);
        return;
    }

    /* Prepare the overlapped structure. */
    memset(&(req->u.io.overlapped), 0, sizeof(req->u.io.overlapped));
    if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
        req->u.io.overlapped.hEvent = (HANDLE)((ULONG_PTR)req->event_handle | 1);
    }

    success = handle->tcp.serv.func_acceptex(handle->socket,
        accept_socket,
        (void*)req->accept_buffer,
        0,
        sizeof(struct sockaddr_storage),
        sizeof(struct sockaddr_storage),
        &bytes,
        &req->u.io.overlapped);

    if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
        /* Process the req without IOCP. */
        req->accept_socket = accept_socket;
        handle->reqs_pending++;
        uv_insert_pending_req(loop, (uv_req_t*)req);
    } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
        /* The req will be processed with IOCP. */
        req->accept_socket = accept_socket;
        handle->reqs_pending++;
        if (handle->flags & UV_HANDLE_EMULATE_IOCP && req->wait_handle == INVALID_HANDLE_VALUE && !RegisterWaitForSingleObject(&req->wait_handle, req->event_handle, post_completion, (void*)req, INFINITE, WT_EXECUTEINWAITTHREAD)) {
            SET_REQ_ERROR(req, GetLastError());
            uv_insert_pending_req(loop, (uv_req_t*)req);
            handle->reqs_pending++;
            return;
        }
    } else {
        /* Make this req pending reporting an error. */
        SET_REQ_ERROR(req, WSAGetLastError());
        uv_insert_pending_req(loop, (uv_req_t*)req);
        handle->reqs_pending++;
        /* Destroy the preallocated client socket. */
        closesocket(accept_socket);
        /* Destroy the event handle */
        if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
            CloseHandle(req->u.io.overlapped.hEvent);
            req->event_handle = NULL;
        }
    }
}

static void uv_tcp_queue_read(uv_loop_t* loop, uv_tcp_t* handle)
{
    uv_read_t* req;
    uv_buf_t buf;
    int result;
    DWORD bytes, flags;

    assert(handle->flags & UV_HANDLE_READING);
    assert(!(handle->flags & UV_HANDLE_READ_PENDING));

    req = &handle->read_req;
    memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));

    /*
   * Preallocate a read buffer if the number of active streams is below
   * the threshold.
  */
    if (loop->active_tcp_streams < uv_active_tcp_streams_threshold) {
        handle->flags &= ~UV_HANDLE_ZERO_READ;
        handle->alloc_cb((uv_handle_t*)handle, 65536, &handle->tcp.conn.read_buffer);
        if (handle->tcp.conn.read_buffer.len == 0) {
            handle->read_cb((uv_stream_t*)handle, UV_ENOBUFS, &handle->tcp.conn.read_buffer);
            return;
        }
        assert(handle->tcp.conn.read_buffer.base != NULL);
        buf = handle->tcp.conn.read_buffer;
    } else {
        handle->flags |= UV_HANDLE_ZERO_READ;
        buf.base = (char*)&uv_zero_;
        buf.len = 0;
    }

    /* Prepare the overlapped structure. */
    memset(&(req->u.io.overlapped), 0, sizeof(req->u.io.overlapped));
    if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
        assert(req->event_handle);
        req->u.io.overlapped.hEvent = (HANDLE)((ULONG_PTR)req->event_handle | 1);
    }

    flags = 0;
    result = WSARecv(handle->socket,
        (WSABUF*)&buf,
        1,
        &bytes,
        &flags,
        &req->u.io.overlapped,
        NULL);

    if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
        /* Process the req without IOCP. */
        handle->flags |= UV_HANDLE_READ_PENDING;
        req->u.io.overlapped.InternalHigh = bytes;
        handle->reqs_pending++;
        uv_insert_pending_req(loop, (uv_req_t*)req);
    } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
        /* The req will be processed with IOCP. */
        handle->flags |= UV_HANDLE_READ_PENDING;
        handle->reqs_pending++;
        if (handle->flags & UV_HANDLE_EMULATE_IOCP && req->wait_handle == INVALID_HANDLE_VALUE && !RegisterWaitForSingleObject(&req->wait_handle, req->event_handle, post_completion, (void*)req, INFINITE, WT_EXECUTEINWAITTHREAD)) {
            SET_REQ_ERROR(req, GetLastError());
            uv_insert_pending_req(loop, (uv_req_t*)req);
        }
    } else {
        /* Make this req pending reporting an error. */
        SET_REQ_ERROR(req, WSAGetLastError());
        uv_insert_pending_req(loop, (uv_req_t*)req);
        handle->reqs_pending++;
    }
}

int uv_tcp_listen(uv_tcp_t* handle, int backlog, uv_connection_cb cb)
{
    uv_loop_t* loop = handle->loop;
    unsigned int i, simultaneous_accepts;
    uv_tcp_accept_t* req;
    int err;

    assert(backlog > 0);

    if (handle->flags & UV_HANDLE_LISTENING) {
        handle->stream.serv.connection_cb = cb;
    }

    if (handle->flags & UV_HANDLE_READING) {
        return WSAEISCONN;
    }

    if (handle->delayed_error) {
        return handle->delayed_error;
    }

    if (!(handle->flags & UV_HANDLE_BOUND)) {
        err = uv_tcp_try_bind(handle,
            (const struct sockaddr*)&uv_addr_ip4_any_,
            sizeof(uv_addr_ip4_any_),
            0);
        if (err)
            return err;
        if (handle->delayed_error)
            return handle->delayed_error;
    }

    if (!handle->tcp.serv.func_acceptex) {
        if (!uv_get_acceptex_function(handle->socket, &handle->tcp.serv.func_acceptex)) {
            return WSAEAFNOSUPPORT;
        }
    }

    if (!(handle->flags & UV_HANDLE_SHARED_TCP_SOCKET) && listen(handle->socket, backlog) == SOCKET_ERROR) {
        return WSAGetLastError();
    }

    handle->flags |= UV_HANDLE_LISTENING;
    handle->stream.serv.connection_cb = cb;
    INCREASE_ACTIVE_COUNT(loop, handle);

    simultaneous_accepts = handle->flags & UV_HANDLE_TCP_SINGLE_ACCEPT ? 1
                                                                       : uv_simultaneous_server_accepts;

    if (!handle->tcp.serv.accept_reqs) {
        handle->tcp.serv.accept_reqs = (uv_tcp_accept_t*)
            uv__malloc(uv_simultaneous_server_accepts * sizeof(uv_tcp_accept_t));
        if (!handle->tcp.serv.accept_reqs) {
            uv_fatal_error(ERROR_OUTOFMEMORY, "uv__malloc");
        }

        for (i = 0; i < simultaneous_accepts; i++) {
            req = &handle->tcp.serv.accept_reqs[i];
            uv_req_init(loop, (uv_req_t*)req);
            req->type = UV_ACCEPT;
            req->accept_socket = INVALID_SOCKET;
            req->data = handle;

            req->wait_handle = INVALID_HANDLE_VALUE;
            if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
                req->event_handle = CreateEvent(NULL, 0, 0, NULL);
                if (!req->event_handle) {
                    uv_fatal_error(GetLastError(), "CreateEvent");
                }
            } else {
                req->event_handle = NULL;
            }

            uv_tcp_queue_accept(handle, req);
        }

        /* Initialize other unused requests too, because uv_tcp_endgame */
        /* doesn't know how how many requests were initialized, so it will */
        /* try to clean up {uv_simultaneous_server_accepts} requests. */
        for (i = simultaneous_accepts; i < uv_simultaneous_server_accepts; i++) {
            req = &handle->tcp.serv.accept_reqs[i];
            uv_req_init(loop, (uv_req_t*)req);
            req->type = UV_ACCEPT;
            req->accept_socket = INVALID_SOCKET;
            req->data = handle;
            req->wait_handle = INVALID_HANDLE_VALUE;
            req->event_handle = NULL;
        }
    }

    return 0;
}

int uv_tcp_accept(uv_tcp_t* server, uv_tcp_t* client)
{
    uv_loop_t* loop = server->loop;
    int err = 0;
    int family;

    uv_tcp_accept_t* req = server->tcp.serv.pending_accepts;

    if (!req) {
        /* No valid connections found, so we error out. */
        return WSAEWOULDBLOCK;
    }

    if (req->accept_socket == INVALID_SOCKET) {
        return WSAENOTCONN;
    }

    if (server->flags & UV_HANDLE_IPV6) {
        family = AF_INET6;
    } else {
        family = AF_INET;
    }

    err = uv_tcp_set_socket(client->loop,
        client,
        req->accept_socket,
        family,
        0);
    if (err) {
        closesocket(req->accept_socket);
    } else {
        uv_connection_init((uv_stream_t*)client);
        /* AcceptEx() implicitly binds the accepted socket. */
        client->flags |= UV_HANDLE_BOUND | UV_HANDLE_READABLE | UV_HANDLE_WRITABLE;
    }

    /* Prepare the req to pick up a new connection */
    server->tcp.serv.pending_accepts = req->next_pending;
    req->next_pending = NULL;
    req->accept_socket = INVALID_SOCKET;

    if (!(server->flags & UV__HANDLE_CLOSING)) {
        /* Check if we're in a middle of changing the number of pending accepts. */
        if (!(server->flags & UV_HANDLE_TCP_ACCEPT_STATE_CHANGING)) {
            uv_tcp_queue_accept(server, req);
        } else {
            /* We better be switching to a single pending accept. */
            assert(server->flags & UV_HANDLE_TCP_SINGLE_ACCEPT);

            server->tcp.serv.processed_accepts++;

            if (server->tcp.serv.processed_accepts >= uv_simultaneous_server_accepts) {
                server->tcp.serv.processed_accepts = 0;
                /*
         * All previously queued accept requests are now processed.
         * We now switch to queueing just a single accept.
         */
                uv_tcp_queue_accept(server, &server->tcp.serv.accept_reqs[0]);
                server->flags &= ~UV_HANDLE_TCP_ACCEPT_STATE_CHANGING;
                server->flags |= UV_HANDLE_TCP_SINGLE_ACCEPT;
            }
        }
    }

    loop->active_tcp_streams++;

    return err;
}

int uv_tcp_read_start(uv_tcp_t* handle, uv_alloc_cb alloc_cb,
    uv_read_cb read_cb)
{
    uv_loop_t* loop = handle->loop;

    handle->flags |= UV_HANDLE_READING;
    handle->read_cb = read_cb;
    handle->alloc_cb = alloc_cb;
    INCREASE_ACTIVE_COUNT(loop, handle);

    /* If reading was stopped and then started again, there could still be a */
    /* read request pending. */
    if (!(handle->flags & UV_HANDLE_READ_PENDING)) {
        if (handle->flags & UV_HANDLE_EMULATE_IOCP && !handle->read_req.event_handle) {
            handle->read_req.event_handle = CreateEvent(NULL, 0, 0, NULL);
            if (!handle->read_req.event_handle) {
                uv_fatal_error(GetLastError(), "CreateEvent");
            }
        }
        uv_tcp_queue_read(loop, handle);
    }

    return 0;
}

static int uv_tcp_try_connect(uv_connect_t* req,
    uv_tcp_t* handle,
    const struct sockaddr* addr,
    unsigned int addrlen,
    uv_connect_cb cb)
{
    uv_loop_t* loop = handle->loop;
    const struct sockaddr* bind_addr;
    BOOL success;
    DWORD bytes;
    int err;

    if (handle->delayed_error) {
        return handle->delayed_error;
    }

    if (!(handle->flags & UV_HANDLE_BOUND)) {
        if (addrlen == sizeof(uv_addr_ip4_any_)) {
            bind_addr = (const struct sockaddr*)&uv_addr_ip4_any_;
        } else if (addrlen == sizeof(uv_addr_ip6_any_)) {
            bind_addr = (const struct sockaddr*)&uv_addr_ip6_any_;
        } else {
            abort();
        }
        err = uv_tcp_try_bind(handle, bind_addr, addrlen, 0);
        if (err)
            return err;
        if (handle->delayed_error)
            return handle->delayed_error;
    }

    if (!handle->tcp.conn.func_connectex) {
        if (!uv_get_connectex_function(handle->socket, &handle->tcp.conn.func_connectex)) {
            return WSAEAFNOSUPPORT;
        }
    }

    uv_req_init(loop, (uv_req_t*)req);
    req->type = UV_CONNECT;
    req->handle = (uv_stream_t*)handle;
    req->cb = cb;
    memset(&req->u.io.overlapped, 0, sizeof(req->u.io.overlapped));

    success = handle->tcp.conn.func_connectex(handle->socket,
        addr,
        addrlen,
        NULL,
        0,
        &bytes,
        &req->u.io.overlapped);

    if (UV_SUCCEEDED_WITHOUT_IOCP(success)) {
        /* Process the req without IOCP. */
        handle->reqs_pending++;
        REGISTER_HANDLE_REQ(loop, handle, req);
        uv_insert_pending_req(loop, (uv_req_t*)req);
    } else if (UV_SUCCEEDED_WITH_IOCP(success)) {
        /* The req will be processed with IOCP. */
        handle->reqs_pending++;
        REGISTER_HANDLE_REQ(loop, handle, req);
    } else {
        return WSAGetLastError();
    }

    return 0;
}

int uv_tcp_getsockname(const uv_tcp_t* handle,
    struct sockaddr* name,
    int* namelen)
{
    int result;

    if (handle->socket == INVALID_SOCKET) {
        return UV_EINVAL;
    }

    if (handle->delayed_error) {
        return uv_translate_sys_error(handle->delayed_error);
    }

    result = getsockname(handle->socket, name, namelen);
    if (result != 0) {
        return uv_translate_sys_error(WSAGetLastError());
    }

    return 0;
}

int uv_tcp_getpeername(const uv_tcp_t* handle,
    struct sockaddr* name,
    int* namelen)
{
    int result;

    if (handle->socket == INVALID_SOCKET) {
        return UV_EINVAL;
    }

    if (handle->delayed_error) {
        return uv_translate_sys_error(handle->delayed_error);
    }

    result = getpeername(handle->socket, name, namelen);
    if (result != 0) {
        return uv_translate_sys_error(WSAGetLastError());
    }

    return 0;
}

int uv_tcp_write(uv_loop_t* loop,
    uv_write_t* req,
    uv_tcp_t* handle,
    const uv_buf_t bufs[],
    unsigned int nbufs,
    uv_write_cb cb)
{
    int result;
    DWORD bytes;

    uv_req_init(loop, (uv_req_t*)req);
    req->type = UV_WRITE;
    req->handle = (uv_stream_t*)handle;
    req->cb = cb;

    /* Prepare the overlapped structure. */
    memset(&(req->u.io.overlapped), 0, sizeof(req->u.io.overlapped));
    if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
        req->event_handle = CreateEvent(NULL, 0, 0, NULL);
        if (!req->event_handle) {
            uv_fatal_error(GetLastError(), "CreateEvent");
        }
        req->u.io.overlapped.hEvent = (HANDLE)((ULONG_PTR)req->event_handle | 1);
        req->wait_handle = INVALID_HANDLE_VALUE;
    }

    result = WSASend(handle->socket,
        (WSABUF*)bufs,
        nbufs,
        &bytes,
        0,
        &req->u.io.overlapped,
        NULL);

    if (UV_SUCCEEDED_WITHOUT_IOCP(result == 0)) {
        /* Request completed immediately. */
        req->u.io.queued_bytes = 0;
        handle->reqs_pending++;
        handle->stream.conn.write_reqs_pending++;
        REGISTER_HANDLE_REQ(loop, handle, req);
        uv_insert_pending_req(loop, (uv_req_t*)req);
    } else if (UV_SUCCEEDED_WITH_IOCP(result == 0)) {
        /* Request queued by the kernel. */
        req->u.io.queued_bytes = uv__count_bufs(bufs, nbufs);
        handle->reqs_pending++;
        handle->stream.conn.write_reqs_pending++;
        REGISTER_HANDLE_REQ(loop, handle, req);
        handle->write_queue_size += req->u.io.queued_bytes;
        if (handle->flags & UV_HANDLE_EMULATE_IOCP && !RegisterWaitForSingleObject(&req->wait_handle, req->event_handle, post_write_completion, (void*)req, INFINITE, WT_EXECUTEINWAITTHREAD | WT_EXECUTEONLYONCE)) {
            SET_REQ_ERROR(req, GetLastError());
            uv_insert_pending_req(loop, (uv_req_t*)req);
        }
    } else {
        /* Send failed due to an error, report it later */
        req->u.io.queued_bytes = 0;
        handle->reqs_pending++;
        handle->stream.conn.write_reqs_pending++;
        REGISTER_HANDLE_REQ(loop, handle, req);
        SET_REQ_ERROR(req, WSAGetLastError());
        uv_insert_pending_req(loop, (uv_req_t*)req);
    }

    return 0;
}

int uv__tcp_try_write(uv_tcp_t* handle,
    const uv_buf_t bufs[],
    unsigned int nbufs)
{
    int result;
    DWORD bytes;

    if (handle->stream.conn.write_reqs_pending > 0)
        return UV_EAGAIN;

    result = WSASend(handle->socket,
        (WSABUF*)bufs,
        nbufs,
        &bytes,
        0,
        NULL,
        NULL);

    if (result == SOCKET_ERROR)
        return uv_translate_sys_error(WSAGetLastError());
    else
        return bytes;
}

void uv_process_tcp_read_req(uv_loop_t* loop, uv_tcp_t* handle,
    uv_req_t* req)
{
    DWORD bytes, flags, err;
    uv_buf_t buf;

    assert(handle->type == UV_TCP);

    handle->flags &= ~UV_HANDLE_READ_PENDING;

    if (!REQ_SUCCESS(req)) {
        /* An error occurred doing the read. */
        if ((handle->flags & UV_HANDLE_READING) || !(handle->flags & UV_HANDLE_ZERO_READ)) {
            handle->flags &= ~UV_HANDLE_READING;
            DECREASE_ACTIVE_COUNT(loop, handle);
            buf = (handle->flags & UV_HANDLE_ZERO_READ) ? uv_buf_init(NULL, 0) : handle->tcp.conn.read_buffer;

            err = GET_REQ_SOCK_ERROR(req);

            if (err == WSAECONNABORTED) {
                /*
         * Turn WSAECONNABORTED into UV_ECONNRESET to be consistent with Unix.
         */
                err = WSAECONNRESET;
            }

            handle->read_cb((uv_stream_t*)handle,
                uv_translate_sys_error(err),
                &buf);
        }
    } else {
        if (!(handle->flags & UV_HANDLE_ZERO_READ)) {
            /* The read was done with a non-zero buffer length. */
            if (req->u.io.overlapped.InternalHigh > 0) {
                /* Successful read */
                handle->read_cb((uv_stream_t*)handle,
                    req->u.io.overlapped.InternalHigh,
                    &handle->tcp.conn.read_buffer);
                /* Read again only if bytes == buf.len */
                if (req->u.io.overlapped.InternalHigh < handle->tcp.conn.read_buffer.len) {
                    goto done;
                }
            } else {
                /* Connection closed */
                if (handle->flags & UV_HANDLE_READING) {
                    handle->flags &= ~UV_HANDLE_READING;
                    DECREASE_ACTIVE_COUNT(loop, handle);
                }
                handle->flags &= ~UV_HANDLE_READABLE;

                buf.base = 0;
                buf.len = 0;
                handle->read_cb((uv_stream_t*)handle, UV_EOF, &handle->tcp.conn.read_buffer);
                goto done;
            }
        }

        /* Do nonblocking reads until the buffer is empty */
        while (handle->flags & UV_HANDLE_READING) {
            handle->alloc_cb((uv_handle_t*)handle, 65536, &buf);
            if (buf.len == 0) {
                handle->read_cb((uv_stream_t*)handle, UV_ENOBUFS, &buf);
                break;
            }
            assert(buf.base != NULL);

            flags = 0;
            if (WSARecv(handle->socket,
                    (WSABUF*)&buf,
                    1,
                    &bytes,
                    &flags,
                    NULL,
                    NULL)
                != SOCKET_ERROR) {
                if (bytes > 0) {
                    /* Successful read */
                    handle->read_cb((uv_stream_t*)handle, bytes, &buf);
                    /* Read again only if bytes == buf.len */
                    if (bytes < buf.len) {
                        break;
                    }
                } else {
                    /* Connection closed */
                    handle->flags &= ~(UV_HANDLE_READING | UV_HANDLE_READABLE);
                    DECREASE_ACTIVE_COUNT(loop, handle);

                    handle->read_cb((uv_stream_t*)handle, UV_EOF, &buf);
                    break;
                }
            } else {
                err = WSAGetLastError();
                if (err == WSAEWOULDBLOCK) {
                    /* Read buffer was completely empty, report a 0-byte read. */
                    handle->read_cb((uv_stream_t*)handle, 0, &buf);
                } else {
                    /* Ouch! serious error. */
                    handle->flags &= ~UV_HANDLE_READING;
                    DECREASE_ACTIVE_COUNT(loop, handle);

                    if (err == WSAECONNABORTED) {
                        /* Turn WSAECONNABORTED into UV_ECONNRESET to be consistent with */
                        /* Unix. */
                        err = WSAECONNRESET;
                    }

                    handle->read_cb((uv_stream_t*)handle,
                        uv_translate_sys_error(err),
                        &buf);
                }
                break;
            }
        }

    done:
        /* Post another read if still reading and not closing. */
        if ((handle->flags & UV_HANDLE_READING) && !(handle->flags & UV_HANDLE_READ_PENDING)) {
            uv_tcp_queue_read(loop, handle);
        }
    }

    DECREASE_PENDING_REQ_COUNT(handle);
}

void uv_process_tcp_write_req(uv_loop_t* loop, uv_tcp_t* handle,
    uv_write_t* req)
{
    int err;

    assert(handle->type == UV_TCP);

    assert(handle->write_queue_size >= req->u.io.queued_bytes);
    handle->write_queue_size -= req->u.io.queued_bytes;

    UNREGISTER_HANDLE_REQ(loop, handle, req);

    if (handle->flags & UV_HANDLE_EMULATE_IOCP) {
        if (req->wait_handle != INVALID_HANDLE_VALUE) {
            UnregisterWait(req->wait_handle);
            req->wait_handle = INVALID_HANDLE_VALUE;
        }
        if (req->event_handle) {
            CloseHandle(req->event_handle);
            req->event_handle = NULL;
        }
    }

    if (req->cb) {
        err = uv_translate_sys_error(GET_REQ_SOCK_ERROR(req));
        if (err == UV_ECONNABORTED) {
            /* use UV_ECANCELED for consistency with Unix */
            err = UV_ECANCELED;
        }
        req->cb(req, err);
    }

    handle->stream.conn.write_reqs_pending--;
    if (handle->stream.conn.shutdown_req != NULL && handle->stream.conn.write_reqs_pending == 0) {
        uv_want_endgame(loop, (uv_handle_t*)handle);
    }

    DECREASE_PENDING_REQ_COUNT(handle);
}

void uv_process_tcp_accept_req(uv_loop_t* loop, uv_tcp_t* handle,
    uv_req_t* raw_req)
{
    uv_tcp_accept_t* req = (uv_tcp_accept_t*)raw_req;
    int err;

    assert(handle->type == UV_TCP);

    /* If handle->accepted_socket is not a valid socket, then */
    /* uv_queue_accept must have failed. This is a serious error. We stop */
    /* accepting connections and report this error to the connection */
    /* callback. */
    if (req->accept_socket == INVALID_SOCKET) {
        if (handle->flags & UV_HANDLE_LISTENING) {
            handle->flags &= ~UV_HANDLE_LISTENING;
            DECREASE_ACTIVE_COUNT(loop, handle);
            if (handle->stream.serv.connection_cb) {
                err = GET_REQ_SOCK_ERROR(req);
                handle->stream.serv.connection_cb((uv_stream_t*)handle,
                    uv_translate_sys_error(err));
            }
        }
    } else if (REQ_SUCCESS(req) && setsockopt(req->accept_socket, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT, (char*)&handle->socket, sizeof(handle->socket)) == 0) {
        req->next_pending = handle->tcp.serv.pending_accepts;
        handle->tcp.serv.pending_accepts = req;

        /* Accept and SO_UPDATE_ACCEPT_CONTEXT were successful. */
        if (handle->stream.serv.connection_cb) {
            handle->stream.serv.connection_cb((uv_stream_t*)handle, 0);
        }
    } else {
        /* Error related to accepted socket is ignored because the server */
        /* socket may still be healthy. If the server socket is broken */
        /* uv_queue_accept will detect it. */
        closesocket(req->accept_socket);
        req->accept_socket = INVALID_SOCKET;
        if (handle->flags & UV_HANDLE_LISTENING) {
            uv_tcp_queue_accept(handle, req);
        }
    }

    DECREASE_PENDING_REQ_COUNT(handle);
}

void uv_process_tcp_connect_req(uv_loop_t* loop, uv_tcp_t* handle,
    uv_connect_t* req)
{
    int err;

    assert(handle->type == UV_TCP);

    UNREGISTER_HANDLE_REQ(loop, handle, req);

    err = 0;
    if (REQ_SUCCESS(req)) {
        if (setsockopt(handle->socket,
                SOL_SOCKET,
                SO_UPDATE_CONNECT_CONTEXT,
                NULL,
                0)
            == 0) {
            uv_connection_init((uv_stream_t*)handle);
            handle->flags |= UV_HANDLE_READABLE | UV_HANDLE_WRITABLE;
            loop->active_tcp_streams++;
        } else {
            err = WSAGetLastError();
        }
    } else {
        err = GET_REQ_SOCK_ERROR(req);
    }
    req->cb(req, uv_translate_sys_error(err));

    DECREASE_PENDING_REQ_COUNT(handle);
}

int uv_tcp_import(uv_tcp_t* tcp, uv__ipc_socket_info_ex* socket_info_ex,
    int tcp_connection)
{
    int err;
    SOCKET socket = WSASocketW(FROM_PROTOCOL_INFO,
        FROM_PROTOCOL_INFO,
        FROM_PROTOCOL_INFO,
        &socket_info_ex->socket_info,
        0,
        WSA_FLAG_OVERLAPPED);

    if (socket == INVALID_SOCKET) {
        return WSAGetLastError();
    }

    err = uv_tcp_set_socket(tcp->loop,
        tcp,
        socket,
        socket_info_ex->socket_info.iAddressFamily,
        1);
    if (err) {
        closesocket(socket);
        return err;
    }

    if (tcp_connection) {
        uv_connection_init((uv_stream_t*)tcp);
        tcp->flags |= UV_HANDLE_READABLE | UV_HANDLE_WRITABLE;
    }

    tcp->flags |= UV_HANDLE_BOUND;
    tcp->flags |= UV_HANDLE_SHARED_TCP_SOCKET;

    tcp->delayed_error = socket_info_ex->delayed_error;

    tcp->loop->active_tcp_streams++;
    return 0;
}

int uv_tcp_nodelay(uv_tcp_t* handle, int enable)
{
    int err;

    if (handle->socket != INVALID_SOCKET) {
        err = uv__tcp_nodelay(handle, handle->socket, enable);
        if (err)
            return err;
    }

    if (enable) {
        handle->flags |= UV_HANDLE_TCP_NODELAY;
    } else {
        handle->flags &= ~UV_HANDLE_TCP_NODELAY;
    }

    return 0;
}

int uv_tcp_keepalive(uv_tcp_t* handle, int enable, unsigned int delay)
{
    int err;

    if (handle->socket != INVALID_SOCKET) {
        err = uv__tcp_keepalive(handle, handle->socket, enable, delay);
        if (err)
            return err;
    }

    if (enable) {
        handle->flags |= UV_HANDLE_TCP_KEEPALIVE;
    } else {
        handle->flags &= ~UV_HANDLE_TCP_KEEPALIVE;
    }

    /* TODO: Store delay if handle->socket isn't created yet. */

    return 0;
}

int uv_tcp_duplicate_socket(uv_tcp_t* handle, int pid,
    LPWSAPROTOCOL_INFOW protocol_info)
{
    if (!(handle->flags & UV_HANDLE_CONNECTION)) {
        /*
     * We're about to share the socket with another process.  Because
     * this is a listening socket, we assume that the other process will
     * be accepting connections on it.  So, before sharing the socket
     * with another process, we call listen here in the parent process.
     */

        if (!(handle->flags & UV_HANDLE_LISTENING)) {
            if (!(handle->flags & UV_HANDLE_BOUND)) {
                return ERROR_INVALID_PARAMETER;
            }

            if (!(handle->delayed_error)) {
                if (listen(handle->socket, SOMAXCONN) == SOCKET_ERROR) {
                    handle->delayed_error = WSAGetLastError();
                }
            }
        }
    }

    if (WSADuplicateSocketW(handle->socket, pid, protocol_info)) {
        return WSAGetLastError();
    }

    handle->flags |= UV_HANDLE_SHARED_TCP_SOCKET;

    return 0;
}

int uv_tcp_simultaneous_accepts(uv_tcp_t* handle, int enable)
{
    if (handle->flags & UV_HANDLE_CONNECTION) {
        return UV_EINVAL;
    }

    /* Check if we're already in the desired mode. */
    if ((enable && !(handle->flags & UV_HANDLE_TCP_SINGLE_ACCEPT)) || (!enable && handle->flags & UV_HANDLE_TCP_SINGLE_ACCEPT)) {
        return 0;
    }

    /* Don't allow switching from single pending accept to many. */
    if (enable) {
        return UV_ENOTSUP;
    }

    /* Check if we're in a middle of changing the number of pending accepts. */
    if (handle->flags & UV_HANDLE_TCP_ACCEPT_STATE_CHANGING) {
        return 0;
    }

    handle->flags |= UV_HANDLE_TCP_SINGLE_ACCEPT;

    /* Flip the changing flag if we have already queued multiple accepts. */
    if (handle->flags & UV_HANDLE_LISTENING) {
        handle->flags |= UV_HANDLE_TCP_ACCEPT_STATE_CHANGING;
    }

    return 0;
}

static int uv_tcp_try_cancel_io(uv_tcp_t* tcp)
{
    SOCKET socket = tcp->socket;
    int non_ifs_lsp;

    /* Check if we have any non-IFS LSPs stacked on top of TCP */
    non_ifs_lsp = (tcp->flags & UV_HANDLE_IPV6) ? uv_tcp_non_ifs_lsp_ipv6 : uv_tcp_non_ifs_lsp_ipv4;

    /* If there are non-ifs LSPs then try to obtain a base handle for the */
    /* socket. This will always fail on Windows XP/3k. */
    if (non_ifs_lsp) {
        DWORD bytes;
        if (WSAIoctl(socket,
                SIO_BASE_HANDLE,
                NULL,
                0,
                &socket,
                sizeof socket,
                &bytes,
                NULL,
                NULL)
            != 0) {
            /* Failed. We can't do CancelIo. */
            return -1;
        }
    }

    assert(socket != 0 && socket != INVALID_SOCKET);

    if (!CancelIo((HANDLE)socket)) {
        return GetLastError();
    }

    /* It worked. */
    return 0;
}

void uv_tcp_close(uv_loop_t* loop, uv_tcp_t* tcp)
{
    int close_socket = 1;

    if (tcp->flags & UV_HANDLE_READ_PENDING) {
        /* In order for winsock to do a graceful close there must not be any */
        /* any pending reads, or the socket must be shut down for writing */
        if (!(tcp->flags & UV_HANDLE_SHARED_TCP_SOCKET)) {
            /* Just do shutdown on non-shared sockets, which ensures graceful close. */
            shutdown(tcp->socket, SD_SEND);

        } else if (uv_tcp_try_cancel_io(tcp) == 0) {
            /* In case of a shared socket, we try to cancel all outstanding I/O, */
            /* If that works, don't close the socket yet - wait for the read req to */
            /* return and close the socket in uv_tcp_endgame. */
            close_socket = 0;

        } else {
            /* When cancelling isn't possible - which could happen when an LSP is */
            /* present on an old Windows version, we will have to close the socket */
            /* with a read pending. That is not nice because trailing sent bytes */
            /* may not make it to the other side. */
        }

    } else if ((tcp->flags & UV_HANDLE_SHARED_TCP_SOCKET) && tcp->tcp.serv.accept_reqs != NULL) {
        /* Under normal circumstances closesocket() will ensure that all pending */
        /* accept reqs are canceled. However, when the socket is shared the */
        /* presence of another reference to the socket in another process will */
        /* keep the accept reqs going, so we have to ensure that these are */
        /* canceled. */
        if (uv_tcp_try_cancel_io(tcp) != 0) {
            /* When cancellation is not possible, there is another option: we can */
            /* close the incoming sockets, which will also cancel the accept */
            /* operations. However this is not cool because we might inadvertently */
            /* close a socket that just accepted a new connection, which will */
            /* cause the connection to be aborted. */
            unsigned int i;
            for (i = 0; i < uv_simultaneous_server_accepts; i++) {
                uv_tcp_accept_t* req = &tcp->tcp.serv.accept_reqs[i];
                if (req->accept_socket != INVALID_SOCKET && !HasOverlappedIoCompleted(&req->u.io.overlapped)) {
                    closesocket(req->accept_socket);
                    req->accept_socket = INVALID_SOCKET;
                }
            }
        }
    }

    if (tcp->flags & UV_HANDLE_READING) {
        tcp->flags &= ~UV_HANDLE_READING;
        DECREASE_ACTIVE_COUNT(loop, tcp);
    }

    if (tcp->flags & UV_HANDLE_LISTENING) {
        tcp->flags &= ~UV_HANDLE_LISTENING;
        DECREASE_ACTIVE_COUNT(loop, tcp);
    }

    if (close_socket) {
        closesocket(tcp->socket);
        tcp->socket = INVALID_SOCKET;
        tcp->flags |= UV_HANDLE_TCP_SOCKET_CLOSED;
    }

    tcp->flags &= ~(UV_HANDLE_READABLE | UV_HANDLE_WRITABLE);
    uv__handle_closing(tcp);

    if (tcp->reqs_pending == 0) {
        uv_want_endgame(tcp->loop, (uv_handle_t*)tcp);
    }
}

int uv_tcp_open(uv_tcp_t* handle, uv_os_sock_t sock)
{
    WSAPROTOCOL_INFOW protocol_info;
    int opt_len;
    int err;

    /* Detect the address family of the socket. */
    opt_len = (int)sizeof protocol_info;
    if (getsockopt(sock,
            SOL_SOCKET,
            SO_PROTOCOL_INFOW,
            (char*)&protocol_info,
            &opt_len)
        == SOCKET_ERROR) {
        return uv_translate_sys_error(GetLastError());
    }

    err = uv_tcp_set_socket(handle->loop,
        handle,
        sock,
        protocol_info.iAddressFamily,
        1);
    if (err) {
        return uv_translate_sys_error(err);
    }

    return 0;
}

/* This function is an egress point, i.e. it returns libuv errors rather than
 * system errors.
 */
int uv__tcp_bind(uv_tcp_t* handle,
    const struct sockaddr* addr,
    unsigned int addrlen,
    unsigned int flags)
{
    int err;

    err = uv_tcp_try_bind(handle, addr, addrlen, flags);
    if (err)
        return uv_translate_sys_error(err);

    return 0;
}

/* This function is an egress point, i.e. it returns libuv errors rather than
 * system errors.
 */
int uv__tcp_connect(uv_connect_t* req,
    uv_tcp_t* handle,
    const struct sockaddr* addr,
    unsigned int addrlen,
    uv_connect_cb cb)
{
    int err;

    err = uv_tcp_try_connect(req, handle, addr, addrlen, cb);
    if (err)
        return uv_translate_sys_error(err);

    return 0;
}
